/*
 * Copyright 1997, Regents of the University of Minnesota
 *
 * srefine.c
 *
 * This file contains code for the separator refinement algortihms
 *
 * Started 8/1/97
 * George
 *
 * $Id: srefine.c,v 1.2 2002/08/10 06:29:34 karypis Exp $
 *
 */

#include <metislib.h>


/*************************************************************************
* This function is the entry point of the separator refinement
**************************************************************************/
void Refine2WayNode(CtrlType *ctrl, GraphType *orggraph, GraphType *graph, float ubfactor)
{

  IFSET(ctrl->dbglvl, DBG_TIME, gk_startcputimer(ctrl->UncoarsenTmr));

  for (;;) {
    IFSET(ctrl->dbglvl, DBG_TIME, gk_startcputimer(ctrl->RefTmr));
    if (ctrl->RType != 15)
      FM_2WayNodeBalance(ctrl, graph, ubfactor); 

    switch (ctrl->RType) {
      case 1:
        FM_2WayNodeRefine(ctrl, graph, ubfactor, 8); 
        break;
      case 2:
        FM_2WayNodeRefine_OneSided(ctrl, graph, ubfactor, 8); 
        break;
      case 3:
        FM_2WayNodeRefine(ctrl, graph, ubfactor, 8); 
        FM_2WayNodeRefine_OneSided(ctrl, graph, ubfactor, 8); 
        break;
      case 4:
        FM_2WayNodeRefine_OneSided(ctrl, graph, ubfactor, 8); 
        FM_2WayNodeRefine(ctrl, graph, ubfactor, 8); 
        break;
      case 5:
        FM_2WayNodeRefineEqWgt(ctrl, graph, 8); 
        break;
    }
    IFSET(ctrl->dbglvl, DBG_TIME, gk_stopcputimer(ctrl->RefTmr));

    if (graph == orggraph) 
      break;

    graph = graph->finer;
    IFSET(ctrl->dbglvl, DBG_TIME, gk_startcputimer(ctrl->ProjectTmr));
    Project2WayNodePartition(ctrl, graph);
    IFSET(ctrl->dbglvl, DBG_TIME, gk_stopcputimer(ctrl->ProjectTmr));
  }

  IFSET(ctrl->dbglvl, DBG_TIME, gk_stopcputimer(ctrl->UncoarsenTmr));
}


/*************************************************************************
* This function allocates memory for 2-way edge refinement
**************************************************************************/
void Allocate2WayNodePartitionMemory(CtrlType *ctrl, GraphType *graph)
{
  idxtype nvtxs;

  nvtxs = graph->nvtxs;

  graph->pwgts  = idxmalloc(3, "Allocate2WayNodePartitionMemory: pwgts");
  graph->where  = idxmalloc(nvtxs, "Allocate2WayNodePartitionMemory: where");
  graph->bndptr = idxmalloc(nvtxs, "Allocate2WayNodePartitionMemory: bndptr");
  graph->bndind = idxmalloc(nvtxs, "Allocate2WayNodePartitionMemory: bndind");
  graph->nrinfo = (NRInfoType *)gk_malloc(nvtxs*sizeof(NRInfoType), "Allocate2WayNodePartitionMemory: nrinfo");
}



/*************************************************************************
* This function computes the initial id/ed 
**************************************************************************/
void Compute2WayNodePartitionParams(CtrlType *ctrl, GraphType *graph)
{
  idxtype i, j, k, l, nvtxs, nbnd;
  idxtype *xadj, *adjncy, *adjwgt, *vwgt;
  idxtype *where, *pwgts, *bndind, *bndptr, *edegrees;
  NRInfoType *rinfo;
  idxtype me, other;

  nvtxs = graph->nvtxs;
  xadj = graph->xadj;
  vwgt = graph->vwgt;
  adjncy = graph->adjncy;
  adjwgt = graph->adjwgt;

  where = graph->where;
  rinfo = graph->nrinfo;
  pwgts = idxset(3, 0, graph->pwgts);
  bndind = graph->bndind;
  bndptr = idxset(nvtxs, -1, graph->bndptr);


  /*------------------------------------------------------------
  / Compute now the separator external degrees
  /------------------------------------------------------------*/
  nbnd = 0;
  for (i=0; i<nvtxs; i++) {
    me = where[i];
    pwgts[me] += vwgt[i];

    ASSERT(me >=0 && me <= 2);

    if (me == 2) { /* If it is on the separator do some computations */
      BNDInsert(nbnd, bndind, bndptr, i);

      edegrees = rinfo[i].edegrees;
      edegrees[0] = edegrees[1] = 0;

      for (j=xadj[i]; j<xadj[i+1]; j++) {
        other = where[adjncy[j]];
        if (other != 2)
          edegrees[other] += vwgt[adjncy[j]];
      }
    }
  }

  ASSERT(CheckNodeBnd(graph, nbnd));

  graph->mincut = pwgts[2];
  graph->nbnd = nbnd;
}


/*************************************************************************
* This function computes the initial id/ed 
**************************************************************************/
void Project2WayNodePartition(CtrlType *ctrl, GraphType *graph)
{
  idxtype i, j, nvtxs;
  idxtype *cmap, *where, *cwhere;
  GraphType *cgraph;

  cgraph = graph->coarser;
  cwhere = cgraph->where;

  nvtxs = graph->nvtxs;
  cmap = graph->cmap;

  Allocate2WayNodePartitionMemory(ctrl, graph);
  where = graph->where;
  
  /* Project the partition */
  for (i=0; i<nvtxs; i++) {
    where[i] = cwhere[cmap[i]];
    ASSERTP(where[i] >= 0 && where[i] <= 2, ("%d %d %d %d\n", i, cmap[i], where[i], cwhere[cmap[i]]));
  }

  FreeGraph(graph->coarser, 1);
  graph->coarser = NULL;

  Compute2WayNodePartitionParams(ctrl, graph);
}